This invention relates to systems and methods for monitoring radiation exposure, and more particularly to real-time radiation exposure monitoring systems and methods.
The mission of health physicists in regard to radiation workers is to make their radiation exposure “as low as reasonably achievable”, a Nuclear Regulatory Commission primary radiation protection philosophy known by the acronym “ALARA”, without interfering with the workers' normal job performance. However, in order to accomplish this, the health physicist must first be able to recognize the radiation intensity. Regular survey for radioactive contaminants in a radiation facility using a survey meter is not only a judicious health physics practice, but is also required by Nuclear Regulatory Commission licenses and federal regulations. Failure to perform appropriate surveys can have serious repercussions.
A number of approaches and instruments have been developed and used throughout the years with the goal of locating radioactive sources and quantifying the corresponding radiation exposure. The most common type of radiation detector is a Geiger-Müeller (GM) survey meter, also called a Geiger counter. A conventional GM meter is a handheld meter with a radiation detection probe and an analog display without any means for recording radiation measurements. Thus, if a record is desired, an operator must manually record meter readings on paper or other media. Such readings, of course, do not indicate the position or orientation of the meter with respect to any radiation source, nor do they reveal any information concerning work activities near the radiation source that may have been a factor contributing to a given exposure level. Conventional GM meters and similar instruments are therefore not as useful as they might be to health physicists attempting to obtain an accurate assessment of workplace exposure during performance of (normal) job tasks, and yet such equipment is the mainstay for health physicists in the accomplishment of their mission.
In recent years, in other contexts, the use of real-time instrumentation has been combined with the use of video to perform exposure assessments, e.g., assessments of exposure to air contaminants as described, for example, by James D. McGlothlin et al. in “Dust Control by Ergonomic Design,” Proceedings IXth International Conference on Production Research, 687–694 (1987), and by Michael G. Gressel et al. in “Video Exposure Monitoring—A Means of Studying Sources of Occupational Air Contaminant Exposure, Part I—Video Exposure Monitoring Techniques,” Applied Occupational and Environmental Hygiene 8(4): 334–338 (1993). Despite such existing air monitoring methods, those in the radiation safety field have heretofore been forced to rely on relatively basic equipment and time-consuming techniques for assessing radiation exposure, and have thereby been hampered in their ability to develop effective strategies for reducing workplace exposure to radiation.